Explanation of how the number of participants for analysis was determined.
Includes whether analysis was per protocol, intention to treat, or another method.
Also provides relevant details such as imputation technique, as appropriate.

Echocardiographic Measures of Heart Size and Function: Right Ventricle (RV) End-diastolic Volume Indexed to Body Surface Area (BSA) [ Time Frame: Measured post-Norwood, an average of 17 days post-Norwood ]

Limitations of the study, such as early termination leading to small numbers of participants
analyzed and technical problems with measurement leading to unreliable or uninterpretable data

As in all surgical trials comparing two operations, it was not possible to blind the personnel caring for the subjects to the intervention. However, the components of the primary endpoint, death and transplantation, are discrete objective events.